Biography.com: Eck, Johann Mayer von: A life story in four sentences.
Books Printed in Germany 1537: Johann Eck: Some information about the philosopher, from a rare books exhibit including an early printing of his sermons in Latin translation.
Eck, Johann Maier von: Brief article on this theologian from the 2001 Columbia Encyclopedia.
Johann Eck: Detailed profile by J.P. Kirsch, from the Catholic Encyclopedia.
Johann Eck: Wikipedia article on this enemy of Luther.